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Rainwater Harvesting
Basics The History of rainwater harvesting can be traced back to as early as 4500 BC by the people of the Ur. Ancient Mesopotamia has also left artifacts of rainwater collection and distribution. The constant demand for clean, fresh water has ensured rainwater harvesting practices have been in use for centuries. Current rainwater collection can be as simple as a rain barrel connected to your roof gutter and used for light landscaping all the way to complex systems intended to filter the rainwater enough to make it potable and be plumbed throughout an entire house. The basic idea is to collect rainwater in anything from cisterns and barrels to pools and ponds. In this page we will discuss the variety of systems available, types of storage, types of filtration, and one of the most important factors in rainwater harvesting, keeping your tanks clean and free of contaminants. http://www.harvesth2o.com/faq.shtml#11 . Storage Systems Many different options are available for water storage. Once you have determined how much rainwater you are going to use you can select the best choice of storage for your needs. Brick and Concrete Cisterns One advantage of concrete cisterns is their weight which helps them stay firmly planted and helps prevent "floating" from ground pressure. Concrete cisterns are also more economical for large-scale systems. Disadvantages include the need to re-seal or line your cistern 10-30 years into its life. Due to size and ground conditions there is a limit of placement options.http://www.rainbrothers.com/cisterns.html Plastic Tanks' '''The most popular style of plastic tank is made from Food Grade and UV resistant Polyethylene. There are many different types of plastic tanks available so you need to make sure you choose a tank that will not leach into your water and has never been used to store chemicals. http://www.rain-barrel.net/rainwater-tanks.html '''Metal Tanks' Manufactured out of copper, stainless, or color polymer coated steel. These materials are usually rust proof and long lasting. Metal tanks hold up excellent against the elements and can withstand extreme temperatures. Wooden Tanks These tanks can be aquired but are expensive and usually just used as show pieces. Bladders' '''Advantages of bladders are their ability to fit in a space that would normally be unuseable such as beneath a house in a crawl space or underneath a deck. The bladder can be completely hidden unlike most above ground tanks. Disadvantages are ability to pop or tear the bladder which if not installed correctly can increase chances of a puncture. Bladders can also be difficult to clean if contaminated. '''Ponds and Pools' One large disadvantage to these forms of storage is they lose alot of water through evaporation. There is a technique using engineered plastic blocks and a liner you can have an in-ground water storage system with a permeable finish top layer so the space can still be enjoyed. http://www.rainxchange.com/ Types of roofing materials good for rainwater harvesting-''' Roofing materials that are not good for potable rainwater harvesting include: asphalt roofing that can crumble and deteriorate particles into the water collection as well as leach petroleum and other chemicals. Wood Shingles are porous and can harbor various types of mold and or fungi. Wooden shingles are also usually treated with harmful chemicals. Metal roofs can be harmful, not necessarily because of the metal but due to the coatings applied as a rust barrier. If you are using a metal roof some investigation into the type of paint or epoxy coating used to seal the product. Most newer smooth metal roofs are good for rain collection. Slate or Clay tiles can be used as well as different fiberglass roofing materials. Newer rubber and EPDM roofing membranes depending on the materials can be excellent for collecting rainwater. http://www.ehow.com/info_7794966_metal-collecting-potable-rain-water.html '''Potable Rainwater- filters and purification Is it possible to get potable water from rainwater? With the right filters and purification systems to ensure the water is safe, rainwater can be made safe for drinking. There are numerous types of filters that include sand filters, micron filters, sock filters and there are also many forms of purification from UV lights to chemical treatments. For more information on this topic please refer to the website below. http://www.harvesth2o.com/filtration_purification.shtml The type of filtration and purification you use on your rainwater can make all the difference. The most important thing to remember when collecting rainwater for potable use is to keep your system well maintained and to not let contaminants get in your system from the start. A good first flush device that captures the first 5-10 gallons is very important. A basic sand filter can be constructed to roughly filter water but must be well maintained. Micron and mesh filters linked in succession to gradually take out any particulate matter and then leading to a sterilizing agent. UV, ozone, chemical treatment. http://t0.gstatic.com/imagesq=tbn:ANd9GcSFRDclwaXBTY05XhEnpig2dp6PdhyLTBmFYnblPKgwhPrdbkq9Aw Different Applications One of the problems I wanted to focus on was the water supply in rural areas with no municipal water. People who are completely dependent on well water have numerous issues to consider, water contamination, ground water levels and the amount of energy consumed in extracting that groundwater. With home rainwater collection you are in control of your water quality and the amount of water you have available. Homeowners with rainwater only systems say that actually seeing your water in the tanks and watching how much your activiities can deplete the water supply and really helps make a difference in conservation. "when you only have what you catch, you become much more aware of the amount of water that you use in everyday tasks." http://www.ecovieenvironmental.com/water-rates Here is a good reference for using rainwater in as many applications at home. http://www.rwh.in/ The Future… I believe the future of rainwater harvesting will be widespread adoption of rain collection for various uses everywhere. While researching this article I was looking into complete rainwater systems on a rural property rather than drilling a well. The first problem was filtering the water enough to make it potable and the second problem was how much water the average household uses per day. The first problem can be dealt with by using a combination of micron filters and UV filters. Some systems even had solar distillation. Having only a rainwater system would require the average family to purchase massive tanks that can hold a large volume of water in case of long spells without precipitation. The houses that we are currently capable of building can have low flow fixtures and appliances as well as drought tolerant landscaping that combined could dramatically reduce the usage of water. External linksEdit *Code of Federal Register - CFR Title 21 Part 129 Helpful information and water tank installation instructions. This is a US Government document, published as part of the Federal Register, these are both government rules and guidelines of water tank installations. *The Texas Manual on Rainwater Harvesting *Guide on saving water around the garden. *Waterwise - Reducing Water in the UK house *Rain barrel construction - Great Lakes Green Initiative *Building a water barrel system *Example and instructions for closed barrel system *How to find local rain barrels *How Rain Diverters work with Rain Barrels Category:Storage Category:Storage